Photosynthesis: The Big Picture

This single reaction has shaped every part of life on Earth:

• Most food chains start with photosynthesis — animal energy usually traces back to plants, algae, or cyanobacteria capturing light, with rare chemosynthetic ecosystems as exceptions
• Atmospheric oxygen exists because photosynthesis split water and released O2 for billions of years
• Fossil fuels are ancient photosynthesis products — coal from forests, oil from marine organisms, gas from decayed organic matter
• Climate regulation relies on plants absorbing CO2, so deforestation speeds up warming by removing this carbon sink
• Artificial photosynthesis is a research frontier aiming to make clean fuels by copying nature.